1. Field of the Invention
The invention relates to a color picture printer, and more particularly, to a paper feeding module of a color picture printer.
2. Description of the Prior Art
A paper feeding module of a color picture printer comprises two rollers for clamping and driving a paper. The paper feeding module must securely clamp the paper along a front-and-rear direction for precise printing of a color picture. When driving the paper, there must be no unwanted displacement of the paper within the paper feeding module. This helps to prevent degradation of printing quality.
Please refer to FIG. 1. FIG. 1 is a perspective view of a paper feeding module 10 of a prior art color picture printer. The paper feeding module 10 comprises a first roller 12 horizontally and rotatably installed inside the housing 11, and a second roller 14 movable along a vertical direction and rotatably installed in contact and in parallel with the first roller 12. The second roller 14 comprises a revolving axle 16 and two cylindrical sleeves 18 mounted on the revolving axle 16 to clamp the paper with the first roller 12. As the first roller 12 and the second roller 14 are rotated in opposite directions, the paper is driven between the first roller 12 and the sleeves 18 of the second roller 14.
Please refer to FIG. 2. FIG. 2 is a perspective view of the paper feeding module 10 with force exerted on its two ends 20. The contact force between the first and second rollers 12, 14 of the prior art color picture printer is generated by imposing force at two ends 20 of the second roller 14. This force is unevenly distributed throughout the revolving axle 16 with the greatest force concentrated at the two ends 20. This causes the bar to bend leading to uneven contact of the first and second rollers 12, 14, unbalanced forward driving force of the paper, and subsequent potential sliding of the paper and degradation of printing quality.